Meaning: 'Difficulty' refers to a challenge or obstacle that makes something hard to achieve.

Wrong options:

• possibility: 'Possibility' is a noun that indicates a chance or potential, which does not convey the challenge implied in the sentence.
• instant: 'Instant' is an adjective that refers to something immediate, which does not fit the context of discussing challenges.
• beholder: 'Beholder' is a noun that refers to a person who observes, which does not serve as a subject in this context.
• smirk: 'Smirk' is a noun that describes a type of smile, which does not relate to the concept of challenge in this sentence.
• physically: 'Physically' is an adverb that describes a manner of being, which does not fit as a subject or noun in this context.
• longer: 'Longer' is a comparative adjective that does not relate to the subject of difficulty and does not fit grammatically.

Correct answer: beholder

Explanation: The term 'beholder' is used as a noun that refers to the person who perceives beauty, fitting grammatically and contextually as it relates to the subjective nature of beauty.

Meaning: 'Beholder' refers to someone who looks at or observes something, particularly in the context of beauty.

Wrong options:

• possibility: 'Possibility' does not fit as it refers to a chance or potential rather than a person observing beauty.
• instant: 'Instant' is an adjective and does not refer to a person, making it grammatically incorrect in this context.
• difficulty: 'Difficulty' is a noun that refers to a challenge, which does not relate to the act of observing beauty.
• smirk: 'Smirk' is a noun describing a type of smile, which does not fit the context of someone perceiving beauty.
• physically: 'Physically' is an adverb that does not refer to a person and is not appropriate in this context.
• longer: 'Longer' is a comparative adjective that does not relate to the concept of a person observing beauty.

Correct answer: smirk

Explanation: The word 'smirk' fits grammatically as a noun that describes a specific type of smile, which aligns with the context of discussing George Bush's facial expression in a political context.

Meaning: 'Smirk' refers to a smug or conceited smile, often implying self-satisfaction or scorn.

Wrong options:

• possibility: 'Possibility' does not fit as it is a noun that refers to a chance, not a facial expression.
• instant: 'Instant' is an adjective that does not describe a facial expression and is grammatically incorrect here.
• difficulty: 'Difficulty' is a noun that refers to a challenge, which does not relate to facial expressions.
• beholder: 'Beholder' is a noun that refers to a person observing, which does not fit as a description of a smile.
• physically: 'Physically' is an adverb that does not relate to facial expressions and is not appropriate in this context.
• longer: 'Longer' is a comparative adjective that does not describe a facial expression and is grammatically incorrect.

Correct answer: physically

Explanation: The word 'physically' fits grammatically as an adverb that describes the manner in which one assesses the president, complementing the political assessment mentioned earlier.

Meaning: 'Physically' refers to the aspect of assessing someone based on their physical appearance.

Wrong options:

• possibility: 'Possibility' does not fit as it is a noun that does not describe a manner of assessment.
• instant: 'Instant' is an adjective that does not relate to the manner of assessing someone and is grammatically incorrect here.
• difficulty: 'Difficulty' is a noun that refers to a challenge, which does not fit the context of assessing someone.
• beholder: 'Beholder' is a noun that refers to a person observing, which does not fit as an adverb describing the manner of assessment.
• smirk: 'Smirk' is a noun that describes a type of smile, which does not fit as a manner of assessment.
• longer: 'Longer' is a comparative adjective that does not relate to the manner of assessing someone and is grammatically incorrect.